Implement shortestpathbounded to respect path length bounds

[nicolas-geysse]

Problem

After fixing #67 with iterativelengthbounded, there's still an edge case: when using ANY SHORTEST with bounds like {1,3}, self-loops (e.g., Daniel→Daniel) can appear with path length 0.

This happens because:

1. iterativelengthbounded(src, dst, lower, upper) correctly finds that a path exists within bounds (e.g., a cycle of length 2)
2. But shortestpath(src, dst) returns the shortest path without respecting bounds (length 0 for self)

Example

FROM GRAPH_TABLE (pg
    MATCH
    p = ANY SHORTEST (a:Person WHERE a.name = 'Daniel')-[k:knows]->{1,3}(b:Person)
    COLUMNS (path_length(p), a.name, b.name)
)

Current behavior: Returns (0, Daniel, Daniel) with path [0]
Expected behavior: Should return the shortest path within bounds or exclude the pair if no such path exists

Proposed Solution

Implement shortestpathbounded(csr_id, v_size, src, dst, lower, upper) that:

1. Finds the shortest path with length between lower and upper
2. Returns NULL/empty if no path exists within bounds
3. Modify GenerateShortestPathCTE in match.cpp to use this function when bounds are specified

Related

• Partially fixed by Fix bounded path results (issue #67) #290
• Original issue: Test if bounded path lengths get correct results #67